Feeling blue may raise women's risk of developing type 2 diabetes, according to new research.
The study shows that symptoms of depression in middle-aged women are associated with higher levels of insulin resistance, which is a precursor to diabetes.
Researchers say the findings may help explain why depression is twice as common among people with diabetes compared with the general population. Depression is also associated with poor diabetes management.
Depression and Diabetes Linked
In the study, which appears in the December issue of Diabetes Care, researchers looked at the association between symptoms of depression and diabetes among a group of 2,662 middle-aged women who took part in the Study of Women's Health Across the Nation. All of the women were free of diabetes when the study began.
Three years later, 97 cases of diabetes were diagnosed among the women.
Researchers found that depression predicted a 66 percent greater risk of diabetes in the women, but this association disappeared after they adjusted for other risk factors associated with the development of diabetes, such as excess fat around the midsection (a heart disease and type 2 diabetes risk factor known as central adiposity).
However, symptoms of depression were linked to greater levels of insulin resistance among the women.
In addition, depressed African-American women were more than 2.5 times more likely to develop diabetes, even after adjusting for other risk factors.
Researchers say the results show that depressive symptoms can increase the risk of diabetes and are related to higher levels of insulin resistance — another risk factor for diabetes.
They add that depression can alter hormones relating to how the body handles stress. This in turn can affect body fat distribution and how it handles blood sugar metabolism.
They say people should be encouraged to seek treatment for depression and maintain and adopt active lifestyles, healthy diets, and weight loss, if needed, to reduce their risk of diabetes.
SOURCE: Everson-Rose, S. Diabetes Care, December 2004; vol 27: pp 2856-2862.